The over-all objective of the proposed research will be to conduct investigations providing information on the modulation which alterations in the activity and the levels of adrenergic amines in the central nervous system (CNS) exert upon the process of the development of addiction to addictive opiates and opioids and which will also furnish findings indicative of whether or not age level of the host animal influences any such modulation of this kind which is found. Specifically, the information to be sought by investigation will seek to determine if alterations in CNS adrenergic amine activities and levels, brought about in laboratory animals (mice and/or rats) during periods encompassing the repetitive administrations of addicting opiates and opioids at the adequate dosage and frequency usually required to produce addiction, will affect development of precipitated withdrawal and/or tolerance related to these addicting agents in mice and/or rats. A major specific objective will be one which is produced by altered CNS adrenergic influence caused in these animals.